From the SOE forums:
On Thursday, October 19, from 2pm PDT until 3pm PDT we will be performing database maintenance which will affect the login servers for EverQuest. During this time period you will be unable to log into the game. We apologize for the inconvenience.
Our next Game Update is scheduled for Wednesday, October 25th starting at approximately 4am PDT. We expect the ETA to be about 6 hours.